Combi Boiler

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What Is a Combi Boiler?

Today, combi boilers are the most common boilers in the UK, which can be attributed to their high efficiency. 

The system works by taking water from the mains and heating it when required. 

Most UK homes prefer combi boilers because the systems provide heat for both radiators and domestic hot water.

Combi boilers are a great choice for their low running cost. 

The system only works when a hot-water outlet – a tap or shower – is turned on. Combi boiler systems also save space as they don’t require much space for keeping a hot water cylinder.

Since energy (heat) is usually lost through hot water tanks in some systems, the absence of a water tank in combi boilers means reduced energy lost. 

The water is heated only when needed and not stored in any container. With this, combi boilers are an efficient energy-saving solution.

How a Combi Boiler Works

Combi boilers are categorized but yet work similarly. 

A combi boiler works with the room thermostat. 

The room thermostat sends a signal to the boiler when the room temperature is below the preset level. 

With this, the boiler produces heat and sends it to the central heating system to heat the home.

The thermostat continues to monitor the temperature, and once it reaches the required level, it sends a signal back to the boiler again, which de-activates the system.

The boiler contains a heat exchanger that transfers the cold mains water to the taps and showers.

Before this occurs, the heat exchanger heats the water up with the heat from the burnt gas. 

Most heat exchangers in these systems are about 90% efficient. 

Depending on how they’re preset, the control valves can only transfer the water to the tap or the central heating at a time and not to the two simultaneously.

Though combi boilers produce continuous water flow, they can only work perfectly with one appliance at a time. 

A slight decline usually occurs when the boiler supplies more than one appliance at a time. 

As such, combination boilers are more suitable for smaller families with fewer members to depend on it for hot water supply simultaneously.

Pros of Combi Boilers

High efficiency: combination boilers are highly efficient because they’re great at providing hot water and supplying heat to the central heating system with low energy consumption.

No water tank required: the combination boiler system heats the hot water and immediately transfer it to the central heating system or the taps when required. 

This avoids the need for a hot water cylinder, saving space in smaller homes.

Less energy loss: heat is usually lost in systems with a water tank, but since combi boilers don’t have a cylinder, less energy is lost, and efficiency of 90% is achievable, saving money on gas bills.

Cons of Combi Boilers

Hassle of installation: installing a combi boiler can be tricky at times. 

The system contains moving parts that require the service of a highly experienced installer. It’s usual to make errors while installing this system than with a conventional boiler.

Suitable for smaller household: combination boilers can only supply hot water for one task (such as the central heating system or the taps) at a time. 

This means that bigger households might find it frustrating having to wait for a task to complete before the other task can take place.

Problems during a breakdown: combination boilers leave no other options for heating the house when they break down. The only option is to heat water with a kettle. 

How Much Does a Combi Boiler Cost?

Two options are available when planning to buy a combi boiler: a new or a used boiler.

However, it’s best to buy a brand new boiler for high efficiency. 

Besides, though it’s cheaper, a second-hand combi boiler has lost a part of its lifetime and might not last long with its new owner. 

Plus, buying a brand new boiler lets you claim the full warranty.

Whether buying a new or used system, two main factors determine the cost: the household’s size and the model quality. 

The size of the household where the system is to be installed contributes to how much a combi boiler cost. 

A 3-bedroom flat can source for its heating needs from a small combi boiler, which only costs around £500-800 while a bigger household will need a bigger boiler costing between £1,200 and £2,000.

Another determinant of how much a combi boiler costs is the model of the boiler. 

Each model differs with quality level and price. As such, expect a more durable, efficient, and quality combi boiler to cost more.

Is A Combi Boiler A Great Choice For Me?

Combination boilers usually take half the number of domestic boiler installations in the UK every year. 

The reason behind this is not far-fetch: combi boilers are more efficient than most other alternatives. They produce reasonable amounts of heat at reasonable costs.

However, the system is more suitable for smaller households with less heating demands. 

If you’re a small family with a shower solution, then consider a combination boiler. 

On the other hand, if you’re a large family with high hot water demand, it might be wise to consider another heating system for your home. 

The reason being that the system can only meet limited hot water needs at a time.

Which Combi Boiler Should I Choose?

Combi boilers are in different types, and the type you choose determines the efficiency to expect.

The efficiency of a combi boiler is rated on a scale of A-G, where ‘A’ stands for excellent and the value decrease towards ‘G’. 

When choosing a combi boiler, ‘size’ plays an important role. 

While you don’t want to buy a bigger boiler than your needs, you also want to buy a boiler that will meet your hot water needs. 

Keep in mind that choosing the right size ensures you play save on your heating bills. 

Comparison: Prices of Combi Boilers to Other Boiler Types

Generally, boilers are expensive, and depending on the brand and type, a boiler can cost between £500 and £2,500. 

Therefore, it’s smart to make inquiries and get as many quotes as possible before deciding which boiler to buy. However, ‘combi’ boiler costs vary from £500 to £2,000.

How Compatible Are Combi Boilers With All Types Of Showers?

Combi boilers are compatible with most standard showers. 

However, the system doesn’t work perfectly with some modern showers. 

For example, coupling this system with a modern multi-jet shower is not always suitable.

Multijet showers function with high water pressure, which is difficult for combi boiler to provide. 

Also, installing a tank fed boiler system is necessary to use pump-assisted showers with a combi boiler.

Do Combi Boilers Offer Good Water Pressure?

Combi boilers provide good water pressure since the water comes directly from the mains.

However, water pressure in a combination boiler reduces with using more appliances at a time.

Therefore, the number of bathrooms you have determines if the system is best for you in term of water pressure. 

If your home has more than one bathroom, you might want to consider another heating system for your household. 

If you still want to go for a combi boiler, then choose a bigger size.

What Size of Combi Boiler is Ideal for My House?

To know the ideal combi boiler size for your home, the first step is to know your home size.

Knowing the size of your house let you know the amount of heat needed. 

For a typical UK home, the ‘rule of thumb’ is that each radiator requires 1.5kW of boiler performance or 70W per m2 for under-floor heating. 

However, it’s best to put your home’s insulation into account when deciding on the right size of combi boiler for your home. 

How insulated your home is, determines the efficiency of the boiler. 

As such, add more kW to your result, or better still, wait until a professional inspects your home and its needs.

What Is the Best Combi Boiler for a Large House?

Different combi boilers brands are available on the market, and it’s often difficult to pinpoint a ‘one cap fit all’ boiler for a large house. 

As such, the best way to go about this is to have a professional inspect your home and recommend which brand is best for you. 

However, excellent combi brands for a large house include Vaillant, Worcester, and Comet.

Ensure you go for a brand and size with high pressure to provide hot water for multiple rooms at a time.

Electric Combi Boiler: An Ideal Type of Combi Boiler

Combi boilers are of different types, and the electric systems are a great option for those on the hunt for a more efficient combi boiler for their households.

Electric combi boiler systems come with an array of advantages compared to oil and gas boilers.

It’s a low-carbon solution, as it releases no gas into the atmosphere. 

Also, electric combi boilers are space-saving since they don’t require extra space for an oil tank.

Electric Combi Boiler Prices

Like the prices of combi boilers generally vary with size and model, electric combi boiler prices vary with these determinants. 

Depending on the size and model, a combi boiler can cost between £1,500 and £4,500. 

While smaller electric combi boilers of 9kW can cost just £1,500, a bigger model can cost £2,500, and a premium model up to £4,500.

Electric boilers are a popular type of boilers in the UK, and the technology is gradually becoming competitive on the market. 

Most UK homes love providing for their heating needs with an electric combi boiler than a gas or oil boiler. 

This is because electric boilers are easy to run and maintain with no noise. 

Are Electric Boilers Cheaper than Gas?

Though electric boilers might not be the cheapest, they have higher efficiency and require lesser maintenance compared to gas and oil boilers. 

The running costs of electric boilers might seem higher, but oil and gas boilers require owners to pay for the yearly gas certificate, which is not so with electric combi boilers. 

Therefore, this should be considered when estimating the difference in running costs of an electric boiler and a fuel boiler. 

Another factor to consider is that though the gas prices might be lower than electricity tariffs, electric combi boilers are more efficient. 

Gas boilers burn more fuel to produce heat, adding to the cost of running. 

It’s also important to consider the government’s financial support for any green investments, which helps owners get paid for every unit of energy produced with their systems. 

Pros and Cons of Electric Combi Boilers

Again, electric boilers have several benefits to offer against their counterparts. 

If you still don’t know what to expect from an electric combi boiler, here’re a few advantages and disadvantages of the system. 

Pros of Electric Combi Boiler:

Completely silent: electric combi boilers don’t make sounds when operating since the moving parts don’t have to move faster to generate heat.

Energy-efficient: generally, combi boiler systems have high-efficiency rates, but the efficiency is higher in electric combi boilers, which can be up to 99.9%.

Environmentally-friendly: today, the UK is gradually shifting to low-carbon heating systems, and electric combi boilers are a great fit for the job. The systems don’t require fossil fuels to run will, therefore, reduce your home’s carbon footprint.

Displayed output: the systems have a digital display unit that displays the temperature of the water circulating. This lets owners have an idea of when the maximum power output is low.

Lower installation costs: one reason the installation costs of this system is low is the absence of installing gas pipelines. Another cost that usually adds to the cost of installing a boiler is the cost of providing a flue for the waste emissions, which is not so with electric combi boilers.

Compact size: since the system requires no flue, the space required for installation is considerably low.

Low maintenance: electric combi boilers have few mechanical parts, and therefore don’t require regular check-ups compared to their alternatives.

Disadvantages of Electric Combi Boiler:

Not ideal for big homes: generally, combi boilers are not suitable for large houses with high needs, as the systems don’t have the capacity to generate enough heat to meet the needs of large properties.

Power cuts: one common challenge often faced with electric combi is the inability to run during power cuts. As such, they’re not suitable for homes located in areas where power cuts often occur.